Methods and devices for preparation of alimentary granular caviar are known based on the technology of thermostatic control of a solution of the components of caviar, preparation of a mixture for forming the grains by pressing the components through a die under pressure into hot vegetable oil, separation of the grains from the oil, washing, drying, and subsequent processing for improvement of flavor and appearance through coloring and packing.
The method of obtaining alimentary caviar based on the preparation of a mixture containing eggs, fish homogenate, food dye, and salt, forming the grains in oil, and their culinary processing, coloring and packing is also known. The carbon medical absorbent CKT-6A is used as a dyestuff in a quantity of 4-9 weight % to the weight of the mixture for forming grains, after salt has been previously mixed with the dye-stuff (Patent of Russian Federation No. 2002432, A23L, 1/328, publication 15.11.93).
The disadvantage of the known method is that a significant quantity of grains differing from standard size are obtained, requiring sieving of the caviar, leading to reduction of the quantity of the on-the-shelf product. Further, the product has insufficient dietary and nutritional properties because of the use of eggs as one of the main components in the mixture used to form the grains. Use of a carbon medical sorbent in a quantity of nearly 9 weight % of the product limits the application of the on-the-shelf product, as it cannot be used widely as a food product: when even a single portion of 10 g caviar is eaten, a person eats 0.9 g of carbon sorbent, which corresponds to four medical tablets containing 0.25 g, the single preventive medical dose. The regular use of a carbon sorbent in such quantities is not recommended, as it is not metabolized, and it adsorbs useful compounds (hormones, vitamins) and some microorganisms.
Obtaining a delicacy granular product, similar to the caviar of sturgeon fishes, is also known, including the preparation of an albuminous mixture from eggs, gustatory components, salt and dye-stuff, forming capsules by pressing the mixture under pressure into vegetable oil heated at 82-88° C., separating the capsules from the oil, washing the emulsion and subsequently separating the capsules from the emulsion and processing the salt emulsion from the fish components and salt. An alimentary black dye-stuff, prepared from an extract of tea and FeCl3 is used as coloring. The eggs are blended into the forming mixture as a mixture of the whites and yokes in a ratio of 10:1 to 4:1. A yeasty extract and alimentary fats are used for gustatory and aromatic processing. The water emulsion consisting of the egg white and salt is washed. (Patent USSR NO. 1837801, A23L, 1/1328, publication 30.08.93).
The disadvantage of the method is that a significant quantity of grains deviating from standard size are obtained. It is believed that the irregularity of the grains is due to crushing at the time the grains are introduced into hot vegetable oil, when the crumbs are for some time in random (unregulated) motion at high temperature (80-90° C.), promoting change in the shape and size of the grains. Use of eggs as a base component in forming the mixture is a negative factor in the nutritional properties of the product. Use of FeCl3 as a dye-stuff also reduces the organoleptic properties of the product.
Methods of forming grains and a device for obtaining alimentary granular caviar are known based on the technology of preparing a mixture containing eggs, fish homogenate, food dye-stuff and salt, supplying gauged jets of the product into vegetable oil at a temperature of 86-90° C., separating the grains from the oil, flushing with water, processing the gustatory emulsion, coloring, and subsequent packing of the on-the-shelf product. Alimentary black dye-stuff obtained from an extract of tea and FeCl3 at pH 1.8-2.2 is used as coloring. The device for implementation of the method includes a cavity for initial dissolution of the components, outlet tubes with forming heads at the ends, a source of gas pressure connected to the cavity when the components are dissolved, a cylindrical granulating cavity for formation of grains of caviar, a nipple for draining excess liquid installed axially to the cavity for initial dissolution of components in front of the outlet pipes, water jackets around the cavity and the cylindrical part of granulating cavity for thermostatic control of the cavities, and a receptacle at the bottom of the granulating cavity for accumulation of the on-the shelf products (Auth. Cert. USSR No. 1782523, A23L, 1/328, publication 23.12.92).
The disadvantage of the technology is the unstable regime when forming the grains, leading to a significant amount of defective product. A device for manufacture of fish caviar was described in Japan No. 60-52795, 1985. The device consists of a unit for forming the drops of product including the droppers for feeding the special water solution (sole) and a stepped cavity with solution of gel-forming agent with an outlet aperture, where the grains of product are formed; the device is equipped with a unit for separating the grains from the forming liquid, washing, and drying. The deficiency of this device is its lower productive capacity caused by the small cross-section of the dropper channels (0.1-0.2 mm), the low output of the droppers and the low rate of feeding the special water solution to the solution of gel-forming agent.
Devices for the manufacture of imitation grain caviar are known (USSR Certificates No. 276725, 1970, No. 1732507, 1989, patent of RF No. 2029479, 1995). The deficiency of most of these devices is their low productive capacity and the unstable condition during formation of the grains, leading to defective product. In the device of the patent of RF No. 2029479, non-stable operation is caused—on the one hand—by the steady changing of pressure in the outlet apertures while the level of the solution in the cavity declines and by the various trajectories and the character of movement of the grain particles. Thus, defective product is produced in great quantities, because the upper warmed layer of forming liquid (vegetable oil) is mixed by the mechanical mixer and is intensively intermixed with the cold portion of the forming liquid without a clear boundary between the warm and cold regions, so that the process of intermixing of the forming liquid is of chaotic character. Further, if the process of the manufacturing the caviar is performed at a temperature of +15° C. to +40° C., contact with bacterial media in the air causes contamination of the product with pathogenic microflora, leading to a limited validity period of the product.
Thus, all of the above methods and devices for preparation of alimentary granular caviar have some common disadvantages:
1. Obtaining a significant amount of grains deviating from standard size and shape, requiring sieving of the grains, reducing the useful output of the on-the-shelf product.
2. Insufficient organoleptic and nutritional properties because of the use of eggs in preparation of the caviar: the eggs may cause an alimentary allergy in some people.
3. Insufficient ecological cleanness and low-level quality of the product because of use of chemical components for coloring.